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Commit 6e9f23d1 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Frederic Weisbecker
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tracing/kprobes: Show event name in trace output 



Show event name in tracing/trace output. This also fixes kprobes events
format to comply with other tracepoint events formats.

Before patching:
<...>-1447  [001] 1038282.286875: do_sys_open+0x0/0xd6: ...
<...>-1447  [001] 1038282.286878: sys_openat+0xc/0xe <- do_sys_open: ...

After patching:
<...>-1447  [001] 1038282.286875: myprobe: (do_sys_open+0x0/0xd6) ...
<...>-1447  [001] 1038282.286878: myretprobe: (sys_openat+0xc/0xe <- do_sys_open) ...

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090910235345.22412.76527.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent eca0d916

Documentation/trace/kprobetrace.txt

+8 −8
Original line number Diff line number Diff line
@@ -114,7 +114,7 @@ format: 
	field: unsigned long flags;	offset:48;tsize:8;

	field: unsigned long mode;	offset:56;tsize:8;



print fmt: "%lx: dfd=%lx filename=%lx flags=%lx mode=%lx", ip, REC->dfd, REC->filename, REC->flags, REC->mode

print fmt: "(%lx) dfd=%lx filename=%lx flags=%lx mode=%lx", REC->ip, REC->dfd, REC->filename, REC->flags, REC->mode





 You can see that the event has 4 arguments as in the expressions you specified.
@@ -129,15 +129,15 @@ print fmt: "%lx: dfd=%lx filename=%lx flags=%lx mode=%lx", ip, REC->dfd, REC->fi 
#

#           TASK-PID    CPU#    TIMESTAMP  FUNCTION

#              | |       |          |         |

           <...>-1447  [001] 1038282.286875: do_sys_open+0x0/0xd6: dfd=3 filename=7fffd1ec4440 flags=8000 mode=0

           <...>-1447  [001] 1038282.286878: sys_openat+0xc/0xe <- do_sys_open: rv=fffffffffffffffe ra=ffffffff81367a3a

           <...>-1447  [001] 1038282.286885: do_sys_open+0x0/0xd6: dfd=ffffff9c filename=40413c flags=8000 mode=1b6

           <...>-1447  [001] 1038282.286915: sys_open+0x1b/0x1d <- do_sys_open: rv=3 ra=ffffffff81367a3a

           <...>-1447  [001] 1038282.286969: do_sys_open+0x0/0xd6: dfd=ffffff9c filename=4041c6 flags=98800 mode=10

           <...>-1447  [001] 1038282.286976: sys_open+0x1b/0x1d <- do_sys_open: rv=3 ra=ffffffff81367a3a

           <...>-1447  [001] 1038282.286875: myprobe: (do_sys_open+0x0/0xd6) dfd=3 filename=7fffd1ec4440 flags=8000 mode=0

           <...>-1447  [001] 1038282.286878: myretprobe: (sys_openat+0xc/0xe <- do_sys_open) rv=fffffffffffffffe ra=ffffffff81367a3a

           <...>-1447  [001] 1038282.286885: myprobe: (do_sys_open+0x0/0xd6) dfd=ffffff9c filename=40413c flags=8000 mode=1b6

           <...>-1447  [001] 1038282.286915: myretprobe: (sys_open+0x1b/0x1d <- do_sys_open) rv=3 ra=ffffffff81367a3a

           <...>-1447  [001] 1038282.286969: myprobe: (do_sys_open+0x0/0xd6) dfd=ffffff9c filename=4041c6 flags=98800 mode=10

           <...>-1447  [001] 1038282.286976: myretprobe: (sys_open+0x1b/0x1d <- do_sys_open) rv=3 ra=ffffffff81367a3a





 Each line shows when the kernel hits a probe, and <- SYMBOL means kernel

 Each line shows when the kernel hits an event, and <- SYMBOL means kernel

returns from SYMBOL(e.g. "sys_open+0x1b/0x1d <- do_sys_open" means kernel

returns from do_sys_open to sys_open+0x1b).

kernel/trace/trace_kprobe.c

+11 −5
Original line number Diff line number Diff line
@@ -902,10 +902,13 @@ print_kprobe_event(struct trace_iterator *iter, int flags) 
	event = ftrace_find_event(field->ent.type);

	tp = container_of(event, struct trace_probe, event);



	if (!trace_seq_printf(s, "%s: (", tp->call.name))

		goto partial;



	if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))

		goto partial;



	if (!trace_seq_puts(s, ":"))

	if (!trace_seq_puts(s, ")"))

		goto partial;



	for (i = 0; i < field->nargs; i++)
@@ -934,6 +937,9 @@ print_kretprobe_event(struct trace_iterator *iter, int flags) 
	event = ftrace_find_event(field->ent.type);

	tp = container_of(event, struct trace_probe, event);



	if (!trace_seq_printf(s, "%s: (", tp->call.name))

		goto partial;



	if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))

		goto partial;
@@ -943,7 +949,7 @@ print_kretprobe_event(struct trace_iterator *iter, int flags) 
	if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))

		goto partial;



	if (!trace_seq_puts(s, ":"))

	if (!trace_seq_puts(s, ")"))

		goto partial;



	for (i = 0; i < field->nargs; i++)
@@ -1087,7 +1093,7 @@ static int kprobe_event_show_format(struct ftrace_event_call *call, 
		SHOW_FIELD(unsigned long, args[i], tp->args[i].name);

	trace_seq_puts(s, "\n");



	return __probe_event_show_format(s, tp, "%lx:", "ip");

	return __probe_event_show_format(s, tp, "(%lx)", "REC->ip");

}



static int kretprobe_event_show_format(struct ftrace_event_call *call,
@@ -1106,8 +1112,8 @@ static int kretprobe_event_show_format(struct ftrace_event_call *call, 
		SHOW_FIELD(unsigned long, args[i], tp->args[i].name);

	trace_seq_puts(s, "\n");



	return __probe_event_show_format(s, tp, "%lx <- %lx:",

					  "func, ret_ip");

	return __probe_event_show_format(s, tp, "(%lx <- %lx)",

					  "REC->func, REC->ret_ip");

}



#ifdef CONFIG_EVENT_PROFILE